/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.markup.html.form;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import org.apache.wicket.MetaDataKey;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.model.IModel;
import org.apache.wicket.util.convert.ConversionException;
import org.apache.wicket.util.string.AppendingStringBuffer;
import org.apache.wicket.util.string.Strings;
/**
* A multiple choice list component.
*
* @author Jonathan Locke
* @author Johan Compagner
* @author Martijn Dashorst
*
* @param <T>
* The model object type
*/
public class ListMultipleChoice<T> extends AbstractChoice<Collection<T>, T>
{
private static final long serialVersionUID = 1L;
/** Meta key for the retain disabled flag */
static MetaDataKey<Boolean> RETAIN_DISABLED_META_KEY = new MetaDataKey<Boolean>()
{
private static final long serialVersionUID = 1L;
};
/** The default maximum number of rows to display. */
private static final int DEFAULT_MAX_ROWS = 8;
/** The maximum number of rows to display. */
private int maxRows = DEFAULT_MAX_ROWS;
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String)
*/
public ListMultipleChoice(final String id)
{
super(id);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, List)
*/
public ListMultipleChoice(final String id, final List<? extends T> choices)
{
super(id, choices);
}
/**
* Creates a multiple choice list with a maximum number of visible rows.
*
* @param id
* component id
* @param choices
* list of choices
* @param maxRows
* the maximum number of visible rows.
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, List)
*/
public ListMultipleChoice(final String id, final List<? extends T> choices, final int maxRows)
{
super(id, choices);
this.maxRows = maxRows;
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String,
* List,IChoiceRenderer)
*/
public ListMultipleChoice(final String id, final List<? extends T> choices,
final IChoiceRenderer<? super T> renderer)
{
super(id, choices, renderer);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel, List)
*
* @param id
* @param object
* @param choices
*/
@SuppressWarnings("unchecked")
public ListMultipleChoice(final String id, IModel<? extends Collection<T>> object,
final List<? extends T> choices)
{
super(id, (IModel<Collection<T>>)object, choices);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel,
* List,IChoiceRenderer)
*
* @param id
* @param object
* @param choices
* @param renderer
*/
@SuppressWarnings("unchecked")
public ListMultipleChoice(final String id, IModel<? extends Collection<T>> object,
final List<? extends T> choices, final IChoiceRenderer<? super T> renderer)
{
super(id, (IModel<Collection<T>>)object, choices, renderer);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel)
*/
public ListMultipleChoice(String id, IModel<? extends List<? extends T>> choices)
{
super(id, choices);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel,IModel)
*
* @param id
* @param model
* @param choices
*/
@SuppressWarnings("unchecked")
public ListMultipleChoice(String id, IModel<? extends Collection<T>> model,
IModel<? extends List<? extends T>> choices)
{
super(id, (IModel<Collection<T>>)model, choices);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String,
* IModel,IChoiceRenderer)
*/
public ListMultipleChoice(String id, IModel<? extends List<? extends T>> choices,
IChoiceRenderer<? super T> renderer)
{
super(id, choices, renderer);
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel,
* IModel,IChoiceRenderer)
*
* @param id
* @param model
* @param choices
* @param renderer
*/
@SuppressWarnings("unchecked")
public ListMultipleChoice(String id, IModel<? extends Collection<T>> model,
IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer)
{
super(id, (IModel<Collection<T>>)model, choices, renderer);
}
/**
* Sets the number of visible rows in the listbox.
*
* @param maxRows
* the number of visible rows
* @return this
*/
public final ListMultipleChoice<T> setMaxRows(final int maxRows)
{
this.maxRows = maxRows;
return this;
}
/**
* @see FormComponent#getModelValue()
*/
@Override
public final String getModelValue()
{
final AppendingStringBuffer buffer = new AppendingStringBuffer();
final Collection<T> selectedValues = getModelObject();
if (selectedValues != null)
{
final List<? extends T> choices = getChoices();
for (T object : selectedValues)
{
if (buffer.length() > 0)
{
buffer.append(VALUE_SEPARATOR);
}
int index = choices.indexOf(object);
buffer.append(getChoiceRenderer().getIdValue(object, index));
}
}
return buffer.toString();
}
/**
* @see org.apache.wicket.markup.html.form.AbstractChoice#isSelected(Object,int, String)
*/
@Override
protected final boolean isSelected(T choice, int index, String selected)
{
// Have a value at all?
if (selected != null)
{
String idValue = getChoiceRenderer().getIdValue(choice, index);
// Loop through ids
for (final StringTokenizer tokenizer = new StringTokenizer(selected, VALUE_SEPARATOR); tokenizer.hasMoreTokens();)
{
final String id = tokenizer.nextToken();
if (id.equals(idValue))
{
return true;
}
}
}
return false;
}
/**
* @see org.apache.wicket.Component#onComponentTag(ComponentTag)
*/
@Override
protected void onComponentTag(final ComponentTag tag)
{
super.onComponentTag(tag);
tag.put("multiple", "multiple");
if (!tag.getAttributes().containsKey("size"))
{
tag.put("size", Math.min(maxRows, getChoices().size()));
}
}
/**
* @see org.apache.wicket.markup.html.form.FormComponent#convertValue(String[])
*/
@Override
protected Collection<T> convertValue(String[] ids) throws ConversionException
{
if (ids != null && ids.length > 0 && !Strings.isEmpty(ids[0]))
{
return convertChoiceIdsToChoices(ids);
}
else
{
ArrayList<T> result = new ArrayList<>();
addRetainedDisabled(result);
return result;
}
}
/**
* Converts submitted choice ids to choice objects.
*
* @param ids
* choice ids. this array is nonnull and always contains at least one id.
* @return list of choices.
*/
protected List<T> convertChoiceIdsToChoices(String[] ids)
{
ArrayList<T> selectedValues = new ArrayList<>();
// If one or more ids is selected
if (ids != null && ids.length > 0 && !Strings.isEmpty(ids[0]))
{
// Get values that could be selected
final Map<String, T> choiceIds2choiceValues = createChoicesIdsMap();
// Loop through selected indices
for (String id : ids)
{
if (choiceIds2choiceValues.containsKey(id))
{
selectedValues.add(choiceIds2choiceValues.get(id));
}
}
}
addRetainedDisabled(selectedValues);
return selectedValues;
}
/**
* Creates a map of choice IDs to choice values. This map can be used to speed up lookups e.g.
* in {@link #convertChoiceIdsToChoices(String[])}. <strong>Do not store the result of this
* method.</strong> The choices list can change between requests so this map <em>must</em> be
* regenerated.
*
* @return a map.
*/
private Map<String, T> createChoicesIdsMap()
{
final List<? extends T> choices = getChoices();
final Map<String, T> choiceIds2choiceValues = new HashMap<String, T>(choices.size(), 1);
for (int index = 0; index < choices.size(); index++)
{
// Get next choice
final T choice = choices.get(index);
choiceIds2choiceValues.put(getChoiceRenderer().getIdValue(choice, index), choice);
}
return choiceIds2choiceValues;
}
private void addRetainedDisabled(ArrayList<T> selectedValues)
{
if (isRetainDisabledSelected())
{
Collection<T> unchangedModel = getModelObject();
String selected;
{
StringBuilder builder = new StringBuilder();
for (T t : unchangedModel)
{
builder.append(t);
builder.append(';');
}
selected = builder.toString();
}
List<? extends T> choices = getChoices();
for (int i = 0; i < choices.size(); i++)
{
final T choice = choices.get(i);
if (isDisabled(choice, i, selected))
{
if (unchangedModel.contains(choice))
{
if (!selectedValues.contains(choice))
{
selectedValues.add(choice);
}
}
}
}
}
}
/**
* See {@link FormComponent#updateCollectionModel(FormComponent)} for details on how the model
* is updated.
*/
@Override
public void updateModel()
{
FormComponent.updateCollectionModel(this);
}
/**
* If true, choices that were selected in the model but disabled in rendering will be retained
* in the model after a form submit. Example: Choices are [1, 2, 3, 4]. Model collection is [2,
* 4]. In rendering, choices 2 and 3 are disabled ({@link #isDisabled(Object, int, String)}).
* That means that four checkboxes are rendered, checkboxes 2 and 4 are checked, but 2 and 3 are
* not clickable. User checks 1 and unchecks 4. If this flag is off, the model will be updated
* to [1]. This is because the browser does not re-submit a disabled checked checkbox: it only
* submits [1]. Therefore Wicket will only see the [1] and update the model accordingly. If you
* set this flag to true, Wicket will check the model before updating to find choices that were
* selected but disabled. These choices will then be retained, leading to a new model value of
* [1, 2] as (probably) expected by the user. Note that this will lead to additional calls to
* {@link #isDisabled(Object, int, String)}.
*
* @return flag
*/
public boolean isRetainDisabledSelected()
{
Boolean flag = getMetaData(RETAIN_DISABLED_META_KEY);
return (flag != null && flag);
}
/**
* @param retain
* flag
* @return this
* @see #isRetainDisabledSelected()
*/
public ListMultipleChoice<T> setRetainDisabledSelected(boolean retain)
{
setMetaData(RETAIN_DISABLED_META_KEY, (retain) ? true : null);
return this;
}
}